<template>
  <div class="cart">
    <h4>全部商品</h4>
    <div class="cart-main">
      <div class="cart-th">
        <div class="cart-th1">全部</div>
        <div class="cart-th2">商品</div>
        <div class="cart-th3">单价（元）</div>
        <div class="cart-th4">数量</div>
        <div class="cart-th5">小计（元）</div>
        <div class="cart-th6">操作</div>
      </div>
      <!-- 商品列表 -->
      <div class="cart-body" v-if="cart.length">
        <ul v-for="c in cart" class="cart-list" :key="c.id">
          <li class="cart-list-con1">
            <input
              type="checkbox"
              name="chk_list"
              :checked="c.isChecked"
              @change="changeOneGoods(c)"
            />
          </li>
          <li class="cart-list-con2">
            <img :src="c.imgUrl" />
            <div class="item-msg">{{ c.skuName }}</div>
          </li>
          <li class="cart-list-con4">
            <span class="price">{{ c.skuPrice }}</span>
          </li>
          <li class="cart-list-con5">
            <a class="mins" @click="changeNum('decre', c)">-</a>

            <input
              autocomplete="off"
              type="text"
              class="itxt"
              minnum="1"
              :value="c.skuNum"
              @change="changeNum('input', c, $event)"
            />
            <a class="plus" @click="changeNum('incre', c)">+</a>
          </li>
          <li class="cart-list-con6">
            <span class="sum">{{ c.skuPrice * c.skuNum }}</span>
          </li>
          <li class="cart-list-con7">
            <a class="sindelet" @click="deleteOneCart(c.skuId)">删除</a>
            <br />
          </li>
        </ul>
      </div>
      <!-- 商品统计区 -->
    </div>
    <div class="cart-tool" v-if="cart.length">
      <div class="select-all">
        <input
          class="chooseAll"
          type="checkbox"
          :checked="allCartChecked"
          @change="checkAllGoods"
        />
        <span>全选</span>
      </div>
      <div class="option">
        <a @click="batchDelete">删除选中的商品</a>
      </div>
      <div class="money-box">
        <div class="chosed">
          已选择 <span>{{ total }}</span
          >件商品
        </div>
        <div class="sumprice">
          <em>总价（不含运费） ：</em>
          <i class="summoney">{{ totalPrice }}</i>
        </div>
        <div class="sumbtn">
          <a class="sum-btn" href="###" target="_blank">结算</a>
        </div>
      </div>
    </div>
    <!-- 商品为空的提示 -->
    <div class="empty" v-if="!cart.length">
      <h1>购物车空空如也！</h1>
      <img
        src="https://img0.baidu.com/it/u=1499822777,2234673112&fm=253&app=120&size=w931&n=0&f=JPEG&fmt=auto?sec=1679418000&t=392dc737395ea4d621e67038fbbb1b72"
        alt=""
      />
    </div>
  </div>
</template>

<script>
import {
  ReqCartList,
  ReqCheckOneCart,
  ReqBatchCheckAllCart,
  ReqDeleteOneCart,
  ReqBatchDeleteCart,
  ReqAddCart,
} from "@/api";
import { goodsNumReg } from "@/utils";
export default {
  name: "ShopCart",
  data() {
    return {
      cart: [],
    };
  },

  computed: {
    //计算全选
    allCartChecked() {
      return this.cart.every((item) => item.isChecked === 1);
    },
    //计算总数
    total() {
      let n = 0;
      this.cart.forEach((item) => {
        //判断吗是否选中
        if (item.isChecked) {
          //累加每个商品的 skuNum
          n += item.skuNum;
        }
      });

      return n;
    },
    //计算总价
    totalPrice() {
      let n = 0;
      this.cart.forEach((item) => {
        if (item.isChecked) {
          n += item.skuNum * item.skuPrice;
        }
      });
      return n;
    },
  },
  methods: {
    async getCartList() {
      //向后台发送请求获取购物车数据
      let result = await ReqCartList();
      // console.log(result);
      if (result[0]) {
        this.cart = result[0].cartInfoList;
      }
    },
    //切换单个数据的选中状态
    async changeOneGoods(oneCart) {
      //准备数据
      let { skuId, isChecked } = oneCart;
      //更新  isChecked  值
      let newChecked = isChecked === 1 ? 0 : 1;
      //发送请求更新后台的 单个商品选中状态
      await ReqCheckOneCart(skuId, newChecked);
      //同步更新本地的单个商品选中状态
      oneCart.isChecked = newChecked;
    },
    //全选与取消全选    商品的选中状态
    async checkAllGoods(e) {
      //准备数据   isChecked   skuIdList
      //获取的 多选框的 当前的 状态
      let { checked } = e.target;
      //对状态进行处理  取反
      let isChecked = checked ? 1 : 0;

      //准备 skuIdList  数组
      let skuIdList = this.cart.map((item) => item.skuId);

      // 1. 向后台发送请求 更新所有商品的 选中状态
      await ReqBatchCheckAllCart(isChecked, skuIdList);

      // 2. 同步更新本地的 所有商品的 选中状态
      this.cart.forEach((item) => (item.isChecked = isChecked));
    },

    async deleteOneCart(id) {
      if (confirm("确定删除吗?")) {
        //1. 向后台发送去请求 删除某个商品
        await ReqDeleteOneCart(id);

        // 2. 同步删除 前端 的 某个商品
        // 第一种 形式   过滤  filter
        // this.cart = this.cart.filter( item => {
        //   console.log("第一种 形式   过滤  filter");
        //   return item.skuId !== id;
        // })

        // 第二种 形式   splice(index,个数)；    findIndex
        let index = this.cart.findIndex((item) => item.skuId === id);

        this.cart.splice(index, 1);
      }
    },

    async batchDelete() {
      if (confirm("确定删除吗？")) {
        //准备选中的  商品 的 skuIdList
        let skuIdList = [];
        this.cart.forEach((item) => {
          if (item.isChecked === 1) {
            skuIdList.push(item.skuId);
          }
        });
        //1.  向后台发送去请求 删除多个商品
        await ReqBatchDeleteCart(skuIdList);
        //console.log(this.cart);
        // 2. 同步删除前端的 多个商品
        this.cart = this.cart.filter((item) => {
          return !skuIdList.includes(item.skuId);
        });
      }
    },
    //更新购物车的数量
    async changeNum(type, good, e) {
      //判断 操作 类型
      switch (type) {
        case "input": // 输入框
          //当前用户所输入的数量
          let { value } = e.target;
          //验证用户输入的数量是否在 1--200 之间
          if (goodsNumReg.test(value)) {
            //计算插值
            let distNum = value - skuNum;
            // 向后台发送请求，更新商品数量
            await ReqAddCart(skuId, distNum);
            //改变当前数据的  skuNum  和 isChecked
            good.skuNum = parseInt(value);
            good.isChecked = 1;
          } else if (value > 200) {
            //大于200时，应重置为 200
            // 变为200  ，并且发送请求
            //重新计算差值   999  888
            let distNum = 200 - skuNum;
            // 向后台发送请求，更新商品数量
            await ReqAddCart(skuId, distNum);
            // 将当期数据变为200， 并 isChecked
            good.skuNum = e.target.value = 200;
            good.isChecked = 1;
          } else {
            //当用户 输入  字母  汉字  负数  小数时，重置为 当前的数量
            e.target.value = skuNum;
          }
          break;
        case "incre": //加
          if (good.skuNum < 200) {
            // 向后台发送请求，更新商品数量
            await ReqAddCart(skuId, 1);
            //更新当前的数据  和 isChecked
            good.skuNum += 1;
            good.isChecked = 1;
          }
          break;

        case "decre": //减
          if (good.skuNum > 1) {
            // 向后台发送请求，更新商品数量
            await ReqAddCart(skuId, -1);
            //更新当前的数据  和 isChecked
            good.skuNum -= 1;
            good.isChecked = 1;
          }
      }
    },
  },
  mounted() {
    //调用方法
    this.getCartList();
  },
};
</script>

<style lang="less" scoped>
.cart {
  width: 1200px;
  margin: 0 auto;
  h4 {
    margin: 9px 0;
    font-size: 14px;
    line-height: 21px;
  }
  .cart-main {
    .cart-th {
      background: #f5f5f5;
      border: 1px solid #ddd;
      padding: 10px;
      overflow: hidden;
      & > div {
        float: left;
      }
      .cart-th1 {
        width: 25%;
        input {
          vertical-align: middle;
        }
        span {
          vertical-align: middle;
        }
      }
      .cart-th2 {
        width: 25%;
      }
      .cart-th3,
      .cart-th4,
      .cart-th5,
      .cart-th6 {
        width: 12.5%;
      }
    }
    .cart-body {
      margin: 15px 0;
      border: 1px solid #ddd;
      .cart-list {
        padding: 10px;
        border-bottom: 1px solid #ddd;
        overflow: hidden;
        & > li {
          float: left;
        }
        .cart-list-con1 {
          width: 15%;
        }
        .cart-list-con2 {
          width: 35%;
          img {
            width: 82px;
            height: 82px;
            float: left;
          }
          .item-msg {
            float: left;
            width: 150px;
            margin: 0 10px;
            line-height: 18px;
          }
        }
        .cart-list-con4 {
          width: 10%;
        }
        .cart-list-con5 {
          width: 17%;
          .mins {
            border: 1px solid #ddd;
            border-right: 0;
            float: left;
            color: #666;
            width: 6px;
            text-align: center;
            padding: 8px;
            text-decoration: none;
          }
          input {
            border: 1px solid #ddd;
            width: 40px;
            height: 31px;
            float: left;
            text-align: center;
            font-size: 14px;
          }

          .plus {
            border: 1px solid #ddd;
            border-left: 0;
            float: left;
            color: #666;
            width: 6px;
            text-align: center;
            padding: 8px;
            text-decoration: none;
          }
        }

        .cart-list-con6 {
          width: 10%;

          .sum {
            font-size: 16px;
          }
        }

        .cart-list-con7 {
          width: 13%;

          a {
            color: #666;
          }
        }
      }
    }
  }
  .cart-tool {
    overflow: hidden;
    border: 1px solid #ddd;

    .select-all {
      padding: 10px;
      overflow: hidden;
      float: left;

      span {
        vertical-align: middle;
      }

      input {
        vertical-align: middle;
      }
    }

    .option {
      padding: 10px;
      overflow: hidden;
      float: left;

      a {
        float: left;
        padding: 0 10px;
        color: #666;
      }
    }

    .money-box {
      float: right;

      .chosed {
        line-height: 26px;
        float: left;
        padding: 0 10px;
      }

      .sumprice {
        width: 200px;
        line-height: 22px;
        float: left;
        padding: 0 10px;

        .summoney {
          color: #c81623;
          font-size: 16px;
        }
      }

      .sumbtn {
        float: right;
        a {
          display: block;
          position: relative;
          width: 96px;
          height: 52px;
          line-height: 52px;
          color: #fff;
          text-align: center;
          font-size: 18px;
          font-family: "Microsoft YaHei";
          background: #e1251b;
          overflow: hidden;
          text-decoration: none;
          &hover {
            color: white !important;
          }
        }
      }
    }
  }
}

.empty {
  text-align: center;
  color: rgb(184, 182, 182);
  img {
    width: 300px;
    height: 100%;
    margin-bottom: 30px;
  }

  h1 {
    margin: 30px 0;
  }
}
</style>
